1. Technical Field
The present invention relates to a measuring apparatus of sliding friction coefficient for vehicle running road surface and more particularly to a measuring apparatus for measuring a sliding friction coefficient for the purpose of establishing a traffic regulation to restrict the running speed of a vehicle running on snowy and/or frozen road surface as well as to make it compulsory to get the vehicle""s wheels fitted with snow chains to prevent traffic accidents caused from the snowy and/or frozen road surface in the winter period.
2. Prior Art
In the known measuring apparatus of this kind, there are such apparatus for measuring sliding friction coefficient of road surface as installed directly on the road surface, as coupled to and towed by a normal automobile, and as operated during an automobile""s running with a measuring apparatus loaded on the automobile.
While the known apparatus as described above installed directly on the road surface is compact and convenient for transporting, it is necessary to restrict or interrupt vehicle traffic and the like at the time of installing the apparatus and actually measuring, and consequently traffic congestion is created on the road especially where there is a lot of automobile traffic. The measuring apparatus towed by an automobile, on the other hand, can measure the friction coefficient during the automobile""s running and does not restrict or interrupt traffic at the time of measuring, but it is a problem that the size of apparatus is made comparatively larger, and that it requires a comparatively large space for storage when not in use, as this is a type of measuring apparatus which is coupled to and towed by an automobile. Such measuring apparatus for loading on the automobile has been developed to measure the sliding friction coefficient mainly for a rapid transit high-way. The automobile upon which the measuring apparatus is loaded is limited to relatively larger sizes such as a large bus or truck, because the automobile has to be run at a high speed and bear the heavy weight load of the measuring apparatus. Consequently it is very expensive and uneconomical for manufacturing a vehicle suitable therefor or remodeling an existing vehicle properly.
An object of the present invention is to resolve the problems of the prior art as described above and to provide a measuring apparatus of sliding friction coefficient which is extremely compact in construction and can be simply, easily and removably loaded on a compact automobile, and which can measure simply and accurately the sliding friction on the running road surface during an automobile""s running, without interrupting traffic of vehicles such as automobiles.
A measuring apparatus of sliding friction coefficient for vehicle running road surface according to the present invention comprises a measuring wheel supported rotatably on a support frame and a brake unit for braking the measuring wheel, wherein a load cell is provided on the support frame placed in the running direction of the measuring wheel horizontally to a rotating shaft thereof for measuring a tension between the support frame and the measuring wheel occurring from the braking action applied to the measuring wheel, a load cell for measuring a carrying weight loaded on the measuring wheel is provided on the support frame vertically to the rotating shaft of the measuring wheel, and the support frame of the measuring wheel is disposed for elevational movement within a box-like casing which is removably loaded on a compact automobile.